QED
by daisybelle
Summary: or five of Sherlock's experiments John could have really lived without and one he wouldn't mind repeating. Written for the Johnlock Gift Exchange November. Established Relationship.
1. Chapter 1

_**AN:**_ A Johnlock Gift Exchange fic for banditbrineshrimp, based on the prompt ""It's for an experiment, John..."

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In their early days of cohabitation there is always a moment of unpredictability when John comes home and it has of course to do with his flatmate, the world's only Consulting Detective. So John isn't really surprised by the view, although it is rather unusual finding Sherlock crawling over the living room floor.

"Close the door, John, or they will get out." And it obviously doesn't stop Sherlock ordering him around.

"Who will get out?" There is no one to be seen which leaves too many frightening options.

"The grasshoppers."

"The grasshoppers?"

"Yes, you heard me, the grasshoppers."

"Why on earth do we have grasshoppers in the flat?"

"It's for an experiment."

John couldn't suppress the groan.

"What kind of experiment involves grasshoppers?"

"There was murder case in Russia where they found a blood stained grasshopper, which lead to the findings of a murder victim. I wanted to know how much drops of blood change the movement of a grasshopper."

John stares at the other man, speechless for a moment. How on earth could someone try to experiment with blood and grasshoppers?

"You're mad."

It is astonishing how indignant Sherlock still can look, even when he is on all four with completely dishevelled hair.

"This is perfectly sensible experiment. Do you have any idea …"

"And why are you on the floor?" John interrupts before Sherlock can start a whole tirade how incredibly idiotic John is.

"Because I may have left the box open."

Another, more heartfelt groan.

"Oh god. Do you know at least how many grasshoppers you had in the box?"

"45. The pet shop couldn't give me more because they needed them for their reptiles and their next delivery is not until Friday."

Sherlock actually sounded a bit petulant about that.

"So we are now looking for 45 grasshoppers?"

"Only 39, I've already located six", mumbles the Detective, already returning his attention to the floor.

John makes a step forward, a crisp noise that directs Sherlock's gaze back to him.

"Now only 38, but please John, be more careful."

With a sigh and a curse John slowly gets on his knees. "38?"

"Yes, 38, John."

The next three hours turn into something that hopefully will be funny in ten years or so. Sherlock and he scramble through the flat on their knees, suddenly jump up when they hear a chirping noise and dashing to the source. The doctor really hopes that Sherlock's weekly search for any bugs or cameras in the flat is as thorough as he pretends to be. He really doesn't need to have a video of this ridiculous enterprise and even less Mycroft seeing it.

However, they have only found 37 of the escaped grasshoppers, but they haven't heard any noise in the last twenty minutes and John is ready to assume the last one escaped when he opened the flat door. Now he only needs to convince Sherlock of this theory or he will never get any sleep tonight.

"It is possible", Sherlock says all of sudden. John turns to him and can't suppress a smile at the state the detective is in. He is pretty sure he has never seen him so battered and exhausted, even after one of his fits with several sleepless days.

"What is possible?"

"That he escaped through the door. The one you smashed was also near the door, it's only probable that another one went this way."

"So we can stop this ridiculous search?"

"Yes."

"And you will never experiment with living insects again?"

"John!" Judging from the indignant tone Sherlock hasn't come to the same conclusion. "Why on earth should I stop?"

"Because we, two grown-up men, spent the last three hours on our knees to search for fucking grasshoppers."

The blank look on the detective's face shows clearly that this is not a decisive factor. Suddenly John is very tired. He has no energy left to argue with Sherlock about that matter.

"Okay, just get them out of the flat, will you. I go to bed, you should do the same."

Without looking back he goes up to his room and more or less collapses on his bed.

The next morning there is no sign of Sherlock or the grasshoppers for that matter and John enjoys the undisturbed reading of the newspaper. He takes his time with his shower and is only a little bit shocked to find a grasshopper on the mirror looking at him. The doctor carefully takes the toothbrush mug and pulls it over the insect. He takes the mug to the kitchen and releases the little animal. It seems only fitting to set it free, after all it escaped Sherlock's experiment and the chase afterwards.


	2. Chapter 2

Even when John complains regularly about the disproportional distribution on household chores, he certainly doesn't expect any change. So it takes him two complete tours through their flat (with him even looking under the bed), before he decides to ask Mrs Hudson for Sherlock's whereabouts.

He is surprised when he finds his friend in front of the washing machine, staring through the glass door as if expecting the solution to the world's problems. John drops a kiss on the messy curls while trying to get a glimpse at the items in the washing machine. The doctor doesn't really expect clothing, anything else is much more likely, but there seem to be actual clothes in the swirl of foam and water. Clothes that seem a bit familiar.

"What are you doing with my jumper?"

"Testing the effect of various acids on natural fibres. At the moment I'm testing bleach, but I don't expect so many effects."

"Sherlock, why on earth …", John isn't quite sure how his sentence would have ended, but he is pretty certain the correct answer to his outburst wouldn't be what Sherlock explained next.

"It's obvious, isn't it? Practically every washing powder already contains bleach to a certain degree to get the white and shiny effect. And it is rather diluted with the amount of water in the machine."

"No, smart ass, why did you take my jumper for your experiment?" John can't help the irritation in his voice, he really liked that jumper.

"It was the only natural fibre I could find." The 'obviously' was clearly implied and really doesn't help with John's mood.

"What about your silk shirts? I'm pretty sure silk is considered a natural fibre."

"Don't be ridiculous, I'm actually doing you a favour. This jumper was hideous."

"This jumper was a present from my grandfather before I joined the army." John snaps. "I know you don't do sentiment, but I am not …" He stops his rant, caught up in emotion and the urge to make Sherlock understand, at least once.

"Do you know what, forget it."

He turns on his heel and leaves. He doesn't take the time to get his wallet or phone (and it is sheer luck that his keys are still in his trouser pocket); he just stomps out of the front door, crashing it closed behind him. The sound echoes in the hollow of his chest, vibrating through the anger. He clenches his fists, closes his eyes for a moment, takes a deep breath and starts to march.

It takes him two hours of walking through London before he feels that he can think straight again. It takes another hour before he is ready to return. Slowly John enters the hallway, staring at their stairs. He has no idea what to expect and he has no idea what to say. But he probably shouldn't stay glued to the spot. He takes every step carefully until he is in front of their door. When he opens it the discoloured remains of his jumper await him on the coffee table, neatly folded, beside a notepad and a pen.

John stares at the ensemble for a long moment only looking up when he hears steps. Sherlock is coming from the kitchen with a steaming mug. The doctor glances shortly at the mug before he points to the notepad.

"What is this for?"

"I want you to write down every item in your possession that is precious to you, so I won't accidently destroy it" is Sherlock's calm explanation.

"You know that other people simply would leave my things alone?"

"And we both know I'm not like other people." Another calm reply.

John looks at him, questioning, irritated. He thinks about a way to stop Sherlock going through his things, but the detective has never cared very much about boundaries since the first day they met.

"I promise I won't delete it." Sherlock has crossed the distance between them and offers him the mug. John stares at him, registers the serious concern in Sherlock's expression. With a sigh he accepts the mug, taking a sip and settling on their sofa.

"If you do, I allow Anderson one day with your coat."


	3. Chapter 3

The book is quite captivating, so it takes John a while to register the hitherto unknown fumes coming from the kitchen. Unknown because for the first time since they shared a flat, Sherlock seems to cook actually something edible. Curiosity leads John to a closer inspection and upon entering the kitchen he can't help but ask Sherlock.

"Are you actually cooking?"

Of course, this gets him the obvious-eyebrow, but the Detective says nothing else, just holds out a spoon for John to taste. Whatever it is, it tastes delicious. Maybe he should try and convince the man do the cooking from now on. His thoughts must have been apparent for Sherlock.

"I needed something mundane to concentrate on while being stuck on the case, it helps me focus."

John feels a little sting of rejection; usually he is the distraction for Sherlock. Again the Detective is able to read him easily.

"Shagging you would not only distract me but also stop me thinking altogether. And this case is somewhat timesensitive."

The explanation is accompanied by a loving kiss, which is too short for John's liking and followed by him being ushered to set the table. A shake of curls indicate that Sherlock won't eat ("On a case, John"), but at least he sits down with a cup of tea. The food is really delicious and with much regret John pushes his plate away. There is no chance that anything else will fit in his stomach.

The doctor takes up his reading on the sofa, ignoring Sherlock's ramblings on the case and is ignored in return when he decides to go to bed. His rest doesn't last very long, after what felt like minutes he finds himself kneeling in front of their toilet, his stomach clearly unhappy with its contents.

He is suspicious after the first round of vomiting, especially when Sherlock kneels beside him and cools his forehead and neck with a washcloth. He is sure after the second round and a glimpse of a rather peculiar expression, guilt. But he waits until the fourth round and after his stomach stopped convulsing and accepted medication with a gulp of water without another round of nausea before he asks.

"Did you solve the case?"

They lie on their bed, he is curled about the detective, his head on Sherlock's chest, elevated enough to prevent dizziness and nausea, but still comfortable. The Detective strokes soothingly through his hair, his other hand rubbing absentmindedly his back in circles. When John doesn't get an answer, he lifts his head a bit to see the sheepish look the detective gives him. After all these years the man still tends to underestimate him.

"I've read the autopsy report and I remember Baskerville", he offers as explanation.

Sherlock nods as in confirmation, but John knows it is more of a sign of processing John's answer, filing it away under John Watson, M.D.

"Yes, it was the stepbrother."

The hand in his hair gives a little pressure, forcing him down on the chest again.

"I'd really prefer if you stop poisoning me to solve your cases."

"Well, I suppose …"

John jerks his head up, which he immediately regrets, but he interrupts Sherlock nevertheless.

"Don't start poisoning yourself either!"

The gentle pressure is back on his head and he willingly returns to his former position, deliberately taking deep breaths to fight the nausea.

"So you are angry?" Sherlock sounds puzzled.

"Of course I am!" John only manages a mental eye roll, but he is pretty sure Sherlock will pick up on it. "I'm just too bloody exhausted right now. But believe me there will be a lecture tomorrow."

"Okay."

They both know that Sherlock will probably delete it very soon after, but for the moment John finds comfort in preparing his speech while he slowly drifts to sleep.


	4. Chapter 4

In hindsight the closed doors between the living room and the kitchen should have been his first sign that something unpleasant involving one of Sherlock's experiments is about to happen. But John who is simply happy that Sarah had let him go before the end of his shift (since most of their patients seem to enjoy the summer day) opens the door and is immediately greeted with a terrible noise and a flush of a reddish fluid. A reddish fluid that has not only his entire front covered but also the complete kitchen walls and Sherlock who astonishingly is clothed in a lab coat with protective goggles on.

Much, much later when he is clean and calm again he would be able to reconstruct the exact timeline of another catastrophe that happened to the flat. Namely the unlikely coincidence of him opening the door while Sherlock pushed the start button of the blender which contained his self-mixed blood substitute. But right now he is pretty much frozen to the spot. When he gains control over his limbs, he wipes the fluid from his face just in time to see Sherlock stop the blender and grin in delight before he starts his victory dance that is usually reserved for promising murder cases.

"Brilliant. I knew it." John hears his lover exclaim before he spots John in the doorway.

"Oh John, you're home early. Did you see it? It's great, isn't it?"

Sherlock's annoying habit of involving him in a dialogue where essential parts are missing is the final piece that brings the doctor to life again.

"Great? Are you fucking kidding me? You destroyed the kitchen? And the living room for one of your insane experiments?"

Too used to John's temper, Sherlock merely corrected: "Actually the living room was your fault. Why did you open the door?"

"Why did I open the door? Oh, excuse me when I try to access my own kitchen and look for my partner. What the hell were you doing?"

Sherlock's good mood vanishes.

"Proving a point. I don't expect you to understand."

The hint of arrogance with the implications on his intellect are nothing new, however they still get to John sometimes.

"Oh yes, sorry, I forgot I'm an idiot. Well, the idiot will now shower and leave the cleaning up to you."

John stomps in the bathroom, getting rid of his clothes with angry movements. The shower doesn't lighten his mood, but getting out of the flat and the presence of this madman does the trick. After all it is still an unusual sunny afternoon in London and watching other people enjoying their day leaves him contemplating a bit on his life choices. Not in a way that means he will actually change something, but sometimes he wonders what was so wrong with 'Nothing happens to me'.

He isn't surprised when Sherlock sits down beside him, but he eyes the two ice cones warily.

"There is nothing wrong with them!", the detective huffs.

"I've been already subject to one of your experiments today, forgive me if I worry a bit."

"Your involvement was an accident, I didn't expect you to be home so early. Now take your cone."

John wants to say something but in the end he just silently accepts it. They are eating slowly, settling in some uneasy quietness, finally broken by John.

"Okay, tell me about it!"

"I don't think it is suited for the occasion."

The doctor can't resist the disbelieving look.

"That has never stopped you before!"

The answering grin is a bit apologetic until it turns in a stream of words. He is right, talking about a murderous butcher, human blood in a blender and splash marks in an industrial kitchen isn't the best conversation he has ever had over an ice cream cone. But hearing the assurance that Sherlock has hired professionals to clean their flat while they are sitting in the sunshine makes it better. Good enough to take Sherlock's hand and press a light kiss on his knuckles.

"Thank you for the ice cream."


	5. Chapter 5

John is soaked. Problems with the tube force him to disembark earlier and the constant drizzle is slowly getting through his clothes on his skin. He starts to feel the cold and is relieved when he is finally in front of their door. Only 17 steps between him and the warm flat and more importantly a hot bath.

A shiver makes him hurry in the hallway and its warmth is absolutely welcome, although not enough. He already discards his jacket on the stairway, toes off his shoes and is barely in the flat when he pulls his jumper over his head. A slight detour to their table to kiss Sherlock Hello before he heads straight to the bathroom. His shirt gets lost on the way leaving only his jeans, pants and socks to strip off when he is finally there.

Stark naked he pulls the shower curtain away and lets it drop immediately.

"Sherlock!"

The detective arrives unhurried.

"John, you can't use the tub, I need it for my experiment."

"There are bodyparts in the tub and a dead pig. What the hell are you doing?"

"Measuring the time how long it takes lime to decompose a body in a semihumid environment." Sherlock explained off-handedly. "You should get dressed, you are obviously freezing."

"That's what I wanted a hot bath for. To get me warm again." John huffs exasperated. "And how long will this bloody experiment go? I need to shower before I got to the surgery."

"If I knew how long it will take there would be no need for this experiment. Besides there is a shower at the surgery. You can use this. Or you can ask Mrs Hudson, although I would prefer if you don't mention the exact reason for this. She is not always very understanding."

"You ... you ... " Obviously the cold has frozen his ability to speak.

"Yes?"

"Oh, forget it." With a last longing look on the tub he leaves the bathroom, searching their bedroom for warm clothes. As an afterthought he also gets the hot water bottle that Mrs Hudson had given Sherlock when the detective had been ill. He makes himself a nice cup of tea (making it a point to prepare none for Sherlock), still occasionally shivering, and also fills the hot water bottle.

He settles on the sofa with the duvet, the hot water bottle and his tea and hopes for something interesting in television, distracting him from his plans to murder his partner. Sherlock is back at the table, doing god knows what on his laptop (probably plotting his next inconvenient experiment).

"Stop shivering, you're distracting me."

"Oh, I'm sorry. I might be warm if I had gotten my bloody bath. But someone thought he could use our bathroom for one of his insane experiments."

"Okay, then I might propose another experiment that might stop both our sufferings."

"I'm not remotely interested in one of your experiments right now, Sherlock."

"So you prefer to be miserable and cold?"

"I'd prefer for once that I could use things in my flat in the intended way."

"It is our flat. So I make some experiments. You make it sound as if I inconvenience you all the time."

"But it's not normal to have your own laboratory in the kitchen or doing experiments with bodyparts in the tub." John's anger who really hasn't vanished flares up again.

"I'm sorry that I don't fit in your narrow world of normal."

Shit, John knows this voice. They are on the brink of a full-blown argument and that is the last thing he needs today. He closes his eyes for a moment, holding his breath before letting it out again.

"Sherlock, okay listen, I don't want you to be normal. But your experiments affect me too. Especially if they leave the tub out of commission."

Sherlock looks at him for a long time and then nods slowly.

"I'll try to be more considerate for your needs in the future."

"Try this."

John catches his lovers gaze, holding it.

"So this new experiment you were proposing, the one with the benefits for the both of us, what would it be?"

A faint smiles appears around Sherlock's mouth.

"How long does it take an ex-army doctor to get warm again with shared body heat?"

John can feel the answering smile appearing on his face.

"Well, that is indeed an interesting question. I say we should try to find the answer to that."


	6. Chapter 6

"Sherlock, please."

The hoarseness in his voice should probably worry him as medical professional, but he is by now far beyond any worrying, reduced to a begging mess by agile violinist fingers and a talented tongue.

Of course that was to be expected when Sherlock woke him ages ago with the proposition of a new experiment.

"I want to catalogue your skin."

John was rather proud that despite being only half awake and in close proximity to a semi-nude Sherlock he managed to inquire: "I thought you already did that?"

"I did. But now I want to compare it to different textures."

That hadn't sounded unusual for Sherlock, but John learnt his lessons.

"Why?"

"Remember the ex-girlfriend from the Bronson case? She compared the victim's skin to velvet. Which is absurd but when I researched it on the internet I found that people compare human skin to a lot of textures and now I want to know which comes closest to yours."

There was only so much resistance against Sherlock under normal conditions, of course John agreed. And Sherlock started his explorations which involved different scarves (cashmere, silk, satin, velvet and a feather boa), a selection of food (chocolate sauce, cream, ice cream, jam, honey and raspberry syrup) and lots of feathery touches, kisses and licks.

By now John is pretty sure that Sherlock has explored every inch of his body at least twice, only the part where he aches to be touched is left out. The doctor arches his body when the detective returns his attention his right nipple, clenching his fists in the scarves that bind him to the headboard.

"Sherlock, please, please, plea… oh god, Sh…, ple…" He exhales sharply when Sherlock bites, a stark contrast to all the light touches that left him craving for more. He feels more than he actually sees that the other man is smirking, deliberately nibbling once again before looming over his partner.

"No need to hurry, John. We have all day."

"Oh god, you are killing me."

"Oh, I intend to. La petite mort, John, I think you'll like this death."

Sherlock's face is close enough that John can feel the movement of his lips against his own. He closes the distance, surprising the detective. When Sherlock pulls out of the kiss, he tries to follow him, keeping the body contact. The detective deliberately moves further away, chuckling at the desperate sound that escapes the doctor.

He quickly returns for a light kiss before he descends once again on John's chest, but now the maddening soft kisses are exchanged for sucking and biting. John has lost all coherence, is only able to whimper and moan. Especially when he is finally engulfed by Sherlock's hot mouth. Apparently the detective has decided that 'all day' can be interrupted because John won't last, not with the view of Sherlock's lips around his cock and tongue against his slit and the movement of wet heat around him.

A hoarse cry of his lover's name and the world is lost to him. When he slowly comes to his senses he registers Sherlock taking care of himself, his attempts at help prevented by the scarves that are still around his wrist. Sherlock's orgasm leaves him shuddering on John's stomach and it takes a while before he crawls upwards, opening the knots on the doctor's wrists before he settles in his favourite cuddle position. John tightens his arms around the detective and for a long while both of them are content with small caresses. They both drift off to sleep when John states "I think this was so far your best experiment." The satisfied smile on his lover's face is the last thing he sees as he closes his eyes.


End file.
